Until now I'd been using Qemu to develop my 64bit distro, but now that I have a little more free time I'd like to move my work to physical hardware. Is it possible for both 32 and 64bit versions of aros be installed on the same harddrive, so long as theyre on different partitions, and can grub used to accomodate this? Bare in mind I know very little about grub, but the biggest problem I see here is that only one partition will be set to "boot" from within AROS. On OS 3.x to switch between OSes I would just change the selected boot device from within hdtoolbox. Is this an option for AROS here too? Im not infront of my AROS machine at the moment so I may be mistaken, but I seem to recall AROS hdtoolbox being fussy with a user changing things and is quicker to want to destroy data than OS3.x was/is.
Thanks in advance.

Yes, I think this can be done. Each system partition should already have an AROS.boot file to help the kernel find a matching partition.

Yes it can - you just need to use seperate partitions with the necessary boot file as Neil suggested.